Two-rail supervisor with fixed thresholds
The Texas Instruments TPS3306-25DGK is a multi-voltage supervisor that monitors two independent supply rails with fixed thresholds of 2.25V and 2.93V. It asserts an active-low reset signal (open-drain output) whenever either monitored voltage drops below its threshold, and holds reset for a minimum of 70ms after both rails return above threshold. The open-drain output lets you wire-OR the reset signal with other supervisors or pull it up to a different voltage rail. This part is typically used in systems with dual-voltage processors, FPGAs, or ASICs that need a sequenced or supervised power-up, such as industrial controllers, telecom line cards, and embedded computing modules.
The TPS3306-25DGK comes in an 8-VSSOP package (3.00 mm × 3.00 mm body), surface-mount only. The 8-pin MSOP footprint is shared with many other TI supervisors.
It is not qualified for automotive under-hood or extended-temperature applications (125°C). If your design needs a supervisor that operates at 125°C, look at the TLV803 series which is rated to 125°C.
For dual-sourcing or a second-source option, the TLV803EA29VDBZR offers a similar simple reset function with a 2.93V threshold and active-low open-drain output, though its reset timeout is 130ms minimum and its temperature range extends to 125°C — check the pinout compatibility before substituting.